如何获得过滤数据的总和

Question

我是php，mysql的新手。

我在数据库中使用了四列，分别是companyname ， issuedwt ， receiptwt和workloss 。

我在下面的查询中使用，以获取issuewt，receasewt和workloss的总计。

$result = mysql_query("SELECT SUM(issuedwt) AS IssuedTotal, SUM(receiptwt) AS ReceiptTotal, SUM(workloss) AS Balance FROM `worksheet`")
or die(mysql_error());

我想使用基于公司名称的过滤器选项。（例如， companyname ）

如果我过滤company1 ，则总共只需要company1 。 我该怎么办？

Answer 1

您可以使用WHERE子句简单地过滤公司companyname ：

SELECT  
  SUM(issuedwt) AS IssuedTotal, 
  SUM(receiptwt) AS ReceiptTotal,
  SUM(workloss) AS Balance 
FROM `worksheet`
WHERE compamnyname = 'company1' -- for example

这会给你IssuedTotal ， ReceiptTotal ，并Balance了只有company1 。

---

但是，如果要获取公司companyname s和总数的列表，请使用GROUP BY companyname ，但是您仍然可以过滤公司名称：

SELECT companyname, 
  SUM(issuedwt) AS IssuedTotal, 
  SUM(receiptwt) AS ReceiptTotal, 
  SUM(workloss) AS Balance 
FROM `worksheet`
GROUP BY companyname

Answer 2

在查询中添加“ group by”选项将使mysql知道哪些元素属于在一起，并将计算每组的总和：

"SELECT 
  SUM(issuedwt) AS IssuedTotal, 
  SUM(receiptwt) AS ReceiptTotal, 
  SUM(workloss) AS Balance 
  FROM worksheet 
  group by companyname"

http://dev.mysql.com/doc/refman/5.0/en/group-by-functions.html

您始终可以使用“ where”选项来限制显示的公司（从TABLE where COLUMN = VALUE中选择），但是我假设您想获取每个公司的数据； 然后使用分组依据。

Answer 3

尝试这个：

SELECT SUM(issuedwt) AS IssuedTotal, SUM(receiptwt) AS ReceiptTotal, 
       SUM(workloss) AS Balance 
FROM `worksheet`
WHERE companyname = 'company1';

如果要使用公司明智的数据，而不要使用以下查询：

SELECT companyname, SUM(issuedwt) AS IssuedTotal, SUM(receiptwt) AS ReceiptTotal, 
       SUM(workloss) AS Balance 
FROM `worksheet`
GROUP BY companyname;

Answer 4

与查询一起使用GROUP BY子句：

SELECT companyname, SUM(issuedwt) AS IssuedTotal, SUM(receiptwt) AS ReceiptTotal,
SUM(workloss) AS Balance FROM `worksheet`
GROUP BY companyname